SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1d2045e752d9242a26058bf399165d2541467dcce8048448af52917e927763e' 
  AND token = 'AhD5an6BJm7NHkIlGNx6WzYK7yXrIUpEklfBNjyyu4U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}